Generally, a natural Christmas tree has lower branches that extend more than an arm's length around its stand. The tree stand is often covered with decorating paper and snow-imitating wool or is hidden by a manger. Wrapped gifts are stowed around the tree stand for several days and even weeks preceding Christmas eve. Therefore, the reservoir of a tree stand is hardly accessible to add water therein.
For all these reasons, a hose and a funnel are normally used to add water into the reservoir of a tree stand to keep the tree fresh and green during the entire holiday season. In most Christmas tree watering systems, a valve is mounted inside the reservoir of the tree stand to stop the flow of water from the hose and funnel when the water has reached a predetermined level inside the reservoir. The backflow of water inside the funnel indicates a full-reservoir condition.
Numerous Christmas tree watering systems have been developed in the past and have enjoyed varying degrees of success. Some watering systems of the prior art are known to occasionally fail to indicate a full-reservoir condition. This deficiency causes an overflow of water from the reservoir of the tree stand or from the funnel above the tree stand, to the floor. An overflow of water from the reservoir of the tree stand is a particular concern because that water often contains dissolved tree sap and other tree extracts which could stain a carpet permanently.
Christmas tree watering systems of a common type are described in the following documents;
U.S. Pat. No. 5,076,009 issued on Dec. 31, 1991 to Michael Cibor;
U.S. Pat. No. 5,522,179 issued on Jun. 4, 1996 to Peter R. Hollis;
U.S. Pat. No. 5,575,110 issued on Nov. 19, 1996 to Luc. M. Couture;
U.S. Pat. No. 6,073,390 issued on Jun. 13, 2000 to Stephen R. Baudier; and
U.S. Pat. No. 6,260,303 issued on Jul. 17, 2001 to George Lewis Sappenfield.
The type of Christmas tree watering systems described in these documents generally comprises a funnel on a Christmas ornament or at other elevated location along the tree. A hose is connected to the funnel and extends to a valve mounted inside the reservoir of the tree stand. The valve has a float therein moving with the water level inside the reservoir. The float carries a valve disc which coincides with the end of the hose, and blocks the end of the hose when the water in the reservoir rises to a predetermined level.
A second type of watering system is described in the U.S. Pat. No. 5,090,443 issued on Feb. 25, 1992 to Paul S. Jacobsen. This document discloses a float valve in which the end of the water hose is laying against a float. The float moves upward in a casing with the level of water in the reservoir of the tree stand, to bend the hose and block the flow of water inside the hose.
A third type of watering system is described in the U.S. Pat. No. 5,937,574 issued on Aug. 17, 1999 to David R. Jacques. This document discloses a float valve for a Christmas tree stand in which is mounted a float on the end of a lever. The lever is pivoted on a pin through its centre. A stud on the opposite end of the lever pushes a ball away from a valve seat thereby allowing a flow of water through the valve seat. As the float rises, the stud retracts and let the ball fall into the valve seat to block the flow of water through the valve seat.
In the prior art valves of the first and second types, the head pressure from the water inside the hose and the funnel forces the valve's flap or disc to open. In this arrangement, the inertia of a rush of water in the hose, such as in the case of an unsteady filling of the funnel, tends to open the valve, even when the float is partly submerged. Therefore, in order to properly close the valve, the float must first gain sufficient buoyancy to overcome this head pressure.
In the prior art valve of the third type, the inflow of water in the hose acts directly against the ball of the valve forcing it to close unexpectedly or prematurely, thereby generating an overflow of water over the rim of the funnel.
As such, it may be appreciated that there continues to be a need for a new and improved float valve which is not susceptible of slow closure because of a head pressure and is not susceptible of premature closure from a flow surge inside the inlet hose.